Air cycle cooling device employing vortex tube



United States Patent AIR CYCLE COOLING DEVICE EMPLOYIN G VORTEX TUBEHelmut R. Schelp, Pacific Palisades, Calif., assignor to The GarrettCorporation, Los Angeles, Calif, a corporation of California Originalapplication October 14, 1949, Serial No. 121,436. and this applicationApril 5, 1954, Serial No.

12 Claims. (Cl. 62-138) This is a divisional application based on Figs.3, 3a and 4 of my copending application, Serial No. 121,436, filedOctober 14, 1949, for Air Conditioner Employing an Expansion EvaporationAir Cycle.

The invention described herein may be manufactured and used by or forthe United States Government for governmental purposes without thepayment to me of any royalty thereon.

It is an object of the invention to provide a simple device for coolingair wherein air is passed through a vortex tube and wherein means areprovided for sprayinga liquid into the air upstream from the cooled airoutlet of the vortex tube.

A further object of the invention is to provide a cooling device of thecharacter set forth in the preceding paragraph having a spray chamber incommunication with the interior of .the vortex tube, and a furtherobject of the invention is to provide a device of this character whereinthe spray chamber has an outlet for a portion of the air originally fedinto the vortex tube.

A further object of the invention is to provide an air cooling devicehaving a vortex tube with a heat exchanger connected to its cooled airoutlet, having means for spraying, a vaporizable liquid into the airstream upstream from the cooled air outlet of the vortex tube and alsohaving means for applying suction to the outlet of the heat exchanger toelfect an expansion of the air as it passes through the heat exchanger,there being means for passing an independent flow of air to be cooledthrough the heat exchanger in heat exchange relation to the air which ispassed through the vortex tube.

A further object of the invention is to provide a device for cooling atgas having a vortex tube with an inlet and a cooled gas outlet at oneend and a warm gas outlet at the opposite end, there being means forspraying a vaporizable liquid into the gas upstream from the cooled gasoutlet of the vortex tube and there being also heat exchangers connectedto the outlets of the vortex tube and also means for applying suction tothe outlets of these heat exchangers so that there will be ararification of the gas which passes through the heat exchangers.

Further objects and advantages of the invention may be brought out inthe following part of the specification wherein the detailed descriptionof the parts of the invention is for the purpose of disclosure, withoutthe intention of limiting the scope of the invention set forth in theappended claims.

Referring to the drawings which are for illustrative purposes only:

Fig. 1 is a schematic sectional view of a form of my invention employinga vortex tube having a closed rear end;

Fig. 2 is a fragmentary sectional view taken as indicated by the line 22of Fig. l

Fig. 3 is a schematic sectional view showing a form of my inventionemploying a vortex tube having an open rear end.

In the embodiment of the invention shown in Fig. 1,

2,720,091 Patented Oct. 11, 1955 'ice I schematically indicate a vortextube 26 having an axially extending cooled air outlet opening formed inthe front end wall 27a of the vortex tube device 26. From a source ofsupply working air to be cooled is fed from a room or chamber 32 througha duct 31 and a tangentially arranged inlet nozzle 26a into the vortextube 26 adjacent the front end wall 27a thereof. Herein, the term air isused in its broad sense as meaning a combination of gases or a singlegas.

In the vortex or Ranque tube as known to the art, in addition to therelatively small cooled air outlet opening 27 at the front end of thetube, there is a larger opening at the rear end through which therelatively warm or hot stream of air passes. In my present invention,however, this larger opening, indicated at 28 extends into an enlargedspray chamber 29. From the inspection of the drawing, it will beperceived that the wall 28a of the vortex tube extends rearwardly fromthe front end wall 27a and that the chamber 29 is formed. by closing therear end of the tube wall 28a by means of a rounded wall 29a which is acontinuation of the wall 28a.

The cold air outlet 27 of the vortex tube 26 extends through a heatexchanger 33 and the air passing through the exchanger flows to somekind of suction device, such as a suction blower or jet pump, not shown.A stream of conditioning air flows along a main duct 34 under thedriving action of a fan 35 driven by a motor 36 or any source of power.The air from the atmosphere is passed over the exchanger tubes 33a whereit is cooled by the working air and dehumidified before flowing intotheroom 32. While it is preferred to use the room or return air, or exhaustair, as a source of the working air which is passed through the vortextube 26, it is also possible to use atmospheric air instead.

In the system shown in Fig. 1, the special application of the Ranquetube is the important feature. The cold working air flows out throughthe cooled air outlet 27, but the warmer air which normally flows outthrough the larger rear end opening of the Ranque tube as known to theart, is instead met with water spray 30a which issues from a spraynozzle 30 disposed in the chamber portion 29 of the vortex tube 26. Thewet bulb temperature in the chamber 29 will depend on the relativehumidity of the air entering the vortex tube along the conduit 31, thusit is seen that the exhaust air from the room 32 would usually bepreferable to outside air for better efliciency. The warmer air, nowreduced to wet bulb temperature mixes with the colder air leaving thevortex tube by way of the cooled air outlet 27, to the heat exchanger33. As the air becomes heated in passing through the tubes 33a it willevaporate more moisture, thus helping to prevent a temperature rise ofthe air during the tube traverse. Also, in the form of the inventionshown in Fig. 1, a form of expansion nozzle is provided with. the resultthat the air entering the vortex tube is cooled by expansion, and inconjunction with the spray chamber 29 and spray nozzle 30 provides acompact and eflicient arrangement for cooling the air. Water is suppliedto the spray nozzle 30 through a valve P arranged to be regulated bymanipulation of a handle such as shown at 8a. In the form of theinvention shown, the wall forming the spray chamber 29 is a part of orcontinuation of the vortex tube wall 28a, and therefore the spray 30aactually sprays water into the interior of the vortex tube, andtherefore there is additive water in the working air at the timeit is inthe vortex tube and prior to the time the working air leaves the vortextube. 1

In the form of the invention shown in Fig. 3, I provide a source ofworking air shown as a room 32, from which air is delivered through aduct 31 to the inlet nozzle 26a of a vortex tube 26 having a cooled airoutlet 27 in its front end wall 27a. Cooled air from the outlet 27 isconducted through a heat exchanger 33 disposed in an air duct 34. Thelarger opening 28 of the vortex tube 26 merges into a conduit 49 whereinis located a spray head 50, which receives water under pressure from avariable pump P havinga regulating lever 8a, adapted to spray water in afine mist both forwardly and rearwardly. The conduit 49 extends to asecond or auxiliary heat exchanger 57 mounted in the duct 34. The airwhich has passed through the tubes 33a of the heat exchanger 33 enters ashort conduit 58 through which extends a suction means in the form of ajet pipe 59 adapted to carry high pressure air, engine exhaust gas orsteam to provide a jet pump and thus maintain fiow through the vortextube 26. The conduit 58 merges in a second suction means in the form ofa jet pipe 61 extending into a conduit 60 from the secondary heatexchanger 57. The combined flows from the conduit 58 and the pipe 59merge and are blown from the second jet pipe 61 to provide a suction onthe conduit 49 to finally exhaust through an outlet pipe 62.

'flow along the inner surface of the wall of the tube 26 into theconduit 49 where the warm air meets the water spray from the nozzle 50.This air is now reduced to wet bulb temperature by evaporation ofmoisture as it passes :toward the secondary heat exchanger 57. Thecooled air carries along an excess of free moisture, so that the airduring passage through the tubes of the heat exchanger 57 tends toremain cool because increase in temperature enables it to evaporatestill more moisture. There is also free moisturein the air which due tosuction of the device 59 passes in rarefied state from the cold airoutlet 27 of the vortex tube 26 and through the tubes 33a of the heatexchanger 33, so that as this air passes through the tubes 33a it willexpand and free moisture will be evaporated and the air will bemaintained at a lower temperature than if the water spray were notpresent. The speed of the fan 35 should be regulated to provide theproper change of air in the room per unit of time, depending upon thetype of room being air conditioned.

Although the improved forms of vortex tubes have been shown inconjunction with systems wherein working air is cooled and thenemployed, by use of heat exchange means, to cool air which is being fedinto a space which is to be cooled, the usefulness of the vortex tubesis not limited to the system shown, but the cooled air leaving thecooled air outlet 27 may be employed for any purpose for which it issuited. r

I claim:

1. In an air cycle air conditioning system, a vortex tube including anair inlet for working air and a pair of oppositely extending air outletseach of a different diameter, a spray chamber directly connected to saidair outlet of larger diameter and having mounted therein nozzle meansfor introducing a fine spray of water into the working air forevaporative cooling thereof, a heat exchanger directly connected to saidair outlet of smaller diameter and providing a path for said working airafter leaving said expansion device, a suction device including an airinlet for the working air leaving said heat exchanger and including anair discharge outlet open to the atmosphere, means to regulate the flowof water through said nozzle means whereby the moisture content of theworking air issuing from said air discharge outlet is capable ofregulation to obtain total saturation, and duct means to conductconditioning air through said heat exchanger along arpath separate fromthe working air path but in heat exchange relation with respect thereto.

2. An air cycle air conditioning system as defined in claim 1 whereinsaid spray chamber is closed except for its communication with said airoutlet of larger diameter of said tube.

3. In an air cycle air conditioning system, a vortex tube including anair inlet for working air and a pair of oppositely extending air outletseach of a different diameter, means forming a first path for flow of aportion of the working air comprising a conduit extending from said airoutlet of larger diameter and having mounted therein nozzle means forintroducing a fine spray of Water into the working air for evaporativecooling thereof, a first heat exchanger connected to said conduit andhaving an outlet connected to the inlet side of a first suction device,means forming a second path for flow of a portion of the working aircomprising a second heat exchanger directly connected to said air outletof smaller diameter, the outlet of said second heat exchanger beingconnected to the inlet side of a second suction device, means toregulate the flow of water through said nozzle means whereby themoisture content of the working air issuing from said suction devices iscapable of regulation to obtain total saturation, and duct means toconduct conditioning air through said heat exchangers along a pathseparate from the working air paths but in heat exchange relation withrespect thereto.

4. In an air cycle air conditioning system as recited in claim 3, saidfirst and second suction devices being in the form of jet pumpsoperating in series and discharging to the free atmosphere.

5. In an air cycle air conditioning system: a vortex tube; means fordelivering air to the inlet of said vortex tube; piping for conductingcooled air away from the cooled air outlet of said vortex tube; andmeans for delivering a spray of liquid into said air in said tube at apoint spaced axially from said inlet and said cooled air outlet of saidvortex tube.

6. In an air cycle air conditioning system: a vortex tube; means fordelivering air to the inlet of said vortex tube; piping for conductingcooled air away from the cooled air outlet of said vortex tube; meansfor delivering a spray of liquid into said air upstream from said cooledair outlet of said vortex tube; and means for applying suction to theair which leaves said cooled air outlet of said vortex tube.

7. In an air cycle air conditioning system: a vortex tube; means fordelivering air to the inlet of said vortex tube; piping for conductingcooled air away from the cooled air outlet of said vortex tube; meansfor delivering a spray of liquid into said air upstream from said cooledair outlet of said vortex tube; a heat exchanger connected to saidcooled air outlet of said vortex tube; and means for applying suction tothe air as it passes through said heat exchanger.

8. In an air cycle air conditioning system: a vortex tube having aninlet and a cooled air outlet at one end and a chamber at the otherend;'means for delivering air to the inlet of said vortex tube; pipingfor conducting cooled air away from the cooled air outlet of said vortextube; and means for delivering an evaporative liquid to the interior ofsaid chamber.

9. In an air cycle air conditioning system: a vortex tube; means fordelivering air to the inlet of said vortex tube having an air inlet anda cooled air outlet at one end thereof and a warm air outlet at theother end thereof; piping for conducting cooled air away from the cooledair outlet of said vortex tube; means for delivering a. spray of liquidinto said air upstream from said cooled air outlet of said vortex tube;and means applying suction to said outlets of said vortex tube.

10. In an air cycle air conditioning system: a vortex tube; means fordelivering air to the inlet of said vortex tube having an air inlet anda cooled air outlet at one end thereof and a warm air outlet at theother end thereof; piping for conducting cooled air away from the cooledair outlet of said vortex tube; means for delivering a spray of liquidinto said air upstream from said cooled air outlet of said vortex tube;first and second heat exchangers connected respectively to said outletsof said vortex tube so that air from said vortex tube will passtherethrough; and means for passing a flow of air to be cooled throughsaid heat exchangers in heat exchange relation to said first named airwhich passes through said heat exchangers.

11. In an air cycle air conditioning system: a vortex tube; means fordelivering air to the inlet of said vortex tube having an air inlet anda cooled air outlet at one end thereof and a Warm air outlet at theother end thereof; piping for conducting cooled air away from the cooledair outlet of said vortex tube; means for delivering a spray of liquidinto said air upstream from said cooled air outlet of said vortex tube;first and second heat exchangers connected respectively to said outletsof said vortex tube so that air from said vortex tube will passtherethrough; means for passing a flow of air to be cooled through saidheat exchangers in heat exchange relation to said first named air whichpasses through said heat exchangers; and

1 from said cooled air outlet; a spray for delivering a vaporizableliquid into the air which leaves said Warm air outlet of the vortextube; and means to be cooled comprising Walls defining a space connectedto said Warm air outlet so as to receive the fluids which are dischargedtherefrom.

References Cited in the file of this patent UNITED STATES PATENTS1,952,281 Rangue Mar. 27, 1934 FOREIGN PATENTS 482,104 Canada Apr. 11,1952 926,452 France Oct. 2, 1947

